The present invention relates to a remotely controlled alphanumeric and graphic symbol display device incorporating a vertical array of light emitting diodes (LEDs) and digital imaging techniques to display messages, information, advertisements, news etc. The alphanumeric and graphic symbol display is manifested as an illuminated visual display on a stationary screen by the light emitted from the array of LEDs when electrically charged while the arm rotating at a desired speed.
The readily accessible display of news and information, particularly in view of the rapidly changing and increasing speed of modern telecommunications, is becoming increasingly critical for use in commercial enterprises, leisure businesses and to the community at large. Display""s of the type typically known in the industry are currently advantageously provided by electronic display signs, e.g. the xe2x80x9cTravelling Wordxe2x80x9d screen display devices applying conventional LED matrix architecture, for instance LED""s arranged in rows and columns in a matrix configuration, for use in stock exchanges or for public messaging and advertisements were invented, developed and installed in the early 1980s. These screens provided ready access to fiscal information that, by its very nature is constantly and rapidly changing.
The use of LEDs as light sources in patterns of rows and columns for displaying information is well known. Various features are comprehensively described in U.S. Pat. No. 5,796,362 issued to Banks. In that patent are disclosed large modular, electronic display sources comprising a sign controller, sign systems buses for data transmission, display panels, and panel control cards associated with each panel. This display sign supports for example 512 LEDs.
A static display unit is also disclosed in international patent application WO 90/12354 to Stella Communications Limited which is described as mounted on a motor driven, rotary unit. The unit provides cylindrical display from LEDs arranged in vertical columns which sweep around a cylindrical surface. The rotating unit carries a unit for controlling the LEDs and a memory.
Both international application filed by Lumino Licht Electronik GmbH, (xe2x80x9cLuminoxe2x80x9d) numbers WO 97/50070 published on Dec. 31, 1997 and WO 98/33164 published on Jul. 30, 1998, relate to rotational display devices within a housing. WO 97/50070 describes a device for displaying alphanumeric characters and/or symbols, within a rotationally symmetric housing (19) of a transparent and/or translucent material; the housing (19) contains an electric motor (2) with a motor shaft (20) which revolves around a symmetrical axis (21); a carrier (5) which is rotationally fixed to the motor shaft (20) and on which is attached at least one row of light-emitting diodes or groups of light-emitting diodes (6) that are substantially perpendicular to the motor shaft (20); and a circuit board (4) with a control circuit for the light-emitting diodes (6). To improve control of the display device and the LED""s and to provide for a technically simple series production, the display device also has an opto-electronic measuring device (15) made of a transmitter (22) and receiver (23), to measure the rotating speed of the carrier (5) for synchronizing control of the light-emitting diodes (6) with the rotating speed of the carrier (5), the transmitter and receiver are fixed to a rotating structural part of the device on the one hand and to a stationary structural part of the device on the other hand, at a short distance apart. With the use of software the signal picked up by the receiver can be converted into a clear square-wave signal, free from external interference so that the LED-control can be synchronized with the exactly or almost exactly measured rotating speed of the carrier (5). The device according to the invention also contains a mechanical balancing element (6, 8) opposite the carrier (5) in relation to the symmetrical axis (21), wherein the balancing element (7, 8) is a rod (7) of any cross-section, the operating length of which can be shortened, the rod being raised into a substantially horizontal position during operating.
WO 98/33164 relate to a spherical display device with a circuit board (4), accommodated inside a spherical housing (31), with drive and control elements and electronic components, as well as a support (5) rotating inside the housing (31) for light-emitting diodes or light-emitting diode groups (6). Transmission of electric energy onto the circuit board (4) is conducted by contactless inductive energy transmission. It is a critical feature of both WO 97/50070 and WO 98/33164 that contactless inductive transmission of electrical energy and/or data is provided to the circuit board and its circuits. It is also a critical feature to interface the device with programming means to control to the LEDs synchronously with the rotating speed of the carrier which, preferably, is rotated by a synchronous motor.
A disadvantage of the prior art proposals is the use of an induction motor having windings on its rotor connected to a power supply by slip rings or brushes which are disconnected to reduce wear with the slip rings being short circuited so that the rotor functions essentially as a squirrel cage motor (a slip ring induction motor). This type of motor is susceptible to wear and production of electrical noise potentially interfering with data controlling the LED display.
It is an object of the invention to provide a rotating information display system having an architecture that is capable of rapidly receiving and consistently displaying and disseminating any relayed data or information.
It is another object of the invention to provide a display device that is, reliable and easily transportable from one location to another. In particular, the display system has advantages of reliability, cost saving and space-saving, i.e. it can be desk-top size or ceiling or the more usual wall-mount.
It is a still further object of the present invention to provide a device that makes an infinite range of displayed information accessible at reasonable cost to businesses, particularly small businesses and the community-at-large.
Another object of the present invention is to provide a device of the kind set forth in the opening part of this specification, which, in a technically simple and in a wear-free manner, provides reliable energy and data transmission to the circuit board and rotating display elements and display circuits.
To achieve this end, the display device is such, that the electronic motor control for rotating the LED""s, the electronic data transmission control and the circuit board power supply are kept entirely separate, independent and mutually exclusive. This separation is necessary in order that a smooth transmission of data is provided to the circuit board which controls the LED""s. Thus the data flow and transmission to the circuit board and thus the display of the desired information will not be interrupted or interfered with as they would in a device which must simultaneously control the functions and operations of the motor and data transmission.
To this end, the motor is a DC brushless, three-phase motor operated by a series of pulses to accurately control rotational speed. This DC brushless, three-phase motor provides appropriate rotation of the LED""s, operates on a completely separate control circuit, than that used to control the data transmission flow and the inductive energy transmission used as a contactless energy transmission to the circuit board.
According to one aspect of the invention provides a display device for visually displaying illuminated graphic and alphanumeric symbols on a screen, the display device comprising: a tubular drive shaft defining an axis of rotation; a housing substantially encompassing a motor for driving the hollow drive shaft; a PCB supported at one end of the tubular shaft for rotation therewith; an array of light emitting diodes mounted to the PCB for rotation therewith; a central processing unit positioned on the circuit board for controlling an actuation sequence of the light emitting diodes; a contactless rotary transformer for supplying electrical power to the circuit board, central processing unit and light emitting diodes; and an optical receiver positioned on the circuit board for directly receiving display control data for the central processing unit from a remote source through the tubular shaft from an optical transmitter.
According to another aspect of the invention provides a moving display device comprising: a) a vertically oriented LED array for projecting a moving display onto a translucent surface; b) a shaft for rotating the LED array about a longitudinal axis of the shaft, the shaft being tubular; c) an infrared data receiver for receiving control data, for the LED array to produce the moving display, through the tubular shaft along said axis from an infrared data transmitter; d) a CPU to control the LED array in response to the received control data; e) a data entry unit to operate the infrared data transmitter to transmit the control data through the tubular shaft for receipt of the infrared data receiver; f) the rotary contactless transformer for inductively providing power to operate the CPU and LED array; and g) a DC brushless, three-phase electric motor connected to rotate the shaft about said axis of a predetermined rate independent of the control data transmission and CPU and LED array power supply.
According to another aspect of the invention provides a moving display device comprising: a) a vertically oriented LED array for projecting a moving display onto a translucent surface; b) a shaft for rotating the LED array about a longitudinal axis of the shaft, the shaft being tubular; c) an infrared data receiver for receiving control data, for the LED array to produce the moving display, through the tubular shaft along said axis from an infrared data transmitter; d) a rotary contactless transformer for inductively providing power to operate the LED array; and e) a DC brushless, three-phase electric motor connected to rotate the shaft about said axis of a predetermined rate; wherein the power supply for the motor, the control data transmission and the LED array power supply are independent of one another.